const int MAXN = 110; //点数的最大值
const int MAXM = 410; //边数的最大值
const int INF = 0x3f3f3f3f;
namespace ISAP {
struct Edge {
    int to, next, cap, flow;
} edge[MAXM]; //注意是MAXM
int tol;
int head[MAXN];
int gap[MAXN], dep[MAXN], cur[MAXN];
void init() {
    tol = 0;
    memset(head, -1, sizeof(head));
}
void addedge(int u, int v, int w, int rw = 0) {
    edge[tol].to = v;
    edge[tol].cap = w;
    edge[tol].flow = 0;
    edge[tol].next = head[u];
    head[u] = tol++;
    edge[tol].to = u;
    edge[tol].cap = rw;
    edge[tol].flow = 0;
    edge[tol].next = head[v];
    head[v] = tol++;
}
int Q[MAXN];
void BFS(int start, int end) {
    memset(dep, -1, sizeof(dep));
    memset(gap, 0, sizeof(gap));
    gap[0] = 1;
    int front = 0, rear = 0;
    dep[end] = 0;
    Q[rear++] = end;
    while (front != rear) {
        int u = Q[front++];
        for (int i = head[u]; i != -1; i = edge[i].next) {
            int v = edge[i].to;
            if (dep[v] != -1) continue;
            Q[rear++] = v;
            dep[v] = dep[u] + 1;
            gap[dep[v]]++;
        }
    }
}
int S[MAXN];
int sap(int start, int end, int N) // N总点数
{
    BFS(start, end);
    memcpy(cur, head, sizeof(head));
    int top = 0;
    int u = start;
    int ans = 0;
    while (dep[start] < N) {
        if (u == end) {
            int Min = INF;
            int inser;
            for (int i = 0; i < top; i++)
                if (Min > edge[S[i]].cap - edge[S[i]].flow) {
                    Min = edge[S[i]].cap - edge[S[i]].flow;
                    inser = i;
                }
            for (int i = 0; i < top; i++) {
                edge[S[i]].flow += Min;
                edge[S[i] ^ 1].flow -= Min;
            }
            ans += Min;
            top = inser;
            u = edge[S[top] ^ 1].to;
            continue;
        }
        bool flag = false;
        int v;
        for (int i = cur[u]; i != -1; i = edge[i].next) {
            v = edge[i].to;
            if (edge[i].cap - edge[i].flow && dep[v] + 1 == dep[u]) {
                flag = true;
                cur[u] = i;
                break;
            }
        }
        if (flag) {
            S[top++] = cur[u];
            u = v;
            continue;
        }
        int Min = N;
        for (int i = head[u]; i != -1; i = edge[i].next)
            if (edge[i].cap - edge[i].flow && dep[edge[i].to] < Min) {
                Min = dep[edge[i].to];
                cur[u] = i;
            }
        gap[dep[u]]--;
        if (!gap[dep[u]]) return ans;
        dep[u] = Min + 1;
        gap[dep[u]]++;
        if (u != start) u = edge[S[--top] ^ 1].to;
    }
    return ans;
}
} // namespace ISAP
using namespace ISAP;